No self respecting electrician conducts an investigation into a reported electrical fault with a socket and see type instrument and no wonder he couldn't give you a proper report and diagnosis that I hope you didn't pay him for.
And yes there are several tests that can be conducted with the appropriate equipment and knowledge by someone who will be able to locate any issues and provide you with options off rectification to return your electrical installation to a safe, satisfactory and compliant state of operation.
You cannot beat word off mouth recommendations when it comes to finding quality tradesman and electricians are no different. Trust me the best ones don't need to shout about it. You find them they don't find you.